If the evidence exists to legally prove that his company violated the embargo, then the company should face the consequences of those actions. I have no idea what the legal punishment is for embargo violations. I doubt it's too serious, but regardless of Trump being involved, it is fundamental to the rule of law that companies and individuals be held accountable for violations of the country's laws.
Yes, Donald Trump should be held responsible for his company violating the trade embargo with Cuba because it is a federal crime. He willingly did trade with Cuba, even when no one from the US was allowed to travel there. He clearly put his loyalty to the US aside to make money.
Donald Trump is largely responsible and likely very proud of the many unethical decisions that went into what his company needed to do in order to violate the trade embargo with Cuba. He should be held responsible and should be persecuted to the fullest extent of the law. At the very least, he should take responsibility.
Trump is a crook who thinks laws don't apply to him. This is only the latest example. Just another example of why US CANNOT afford to elect Donald Trump as President. Even though diplomatic relations to Cuba have now opened up, the time period Trump's activities took place show a pure disregard for the law. The shoes keep dropping on this very corrupt shyster.